1. Field of Invention
The present invention relates to a scanning and reflecting device, and more particularly to a two-dimensional scanning and reflecting device.
2. Related Art
The main stream of electronic products is light, thin, short, small, and portable at present, and almost all the components develop toward miniaturization, so a micro projector arises. The current micro projector may be divided into the following three different technologies. One is a laser micro projection technology, in which a laser is used as a light source, a micro scanning mirror is manufactured by using a Micro Electronic Mechanical System (MEMS) process, and the micro scanning mirror may scan in horizontal and vertical axial directions, and rapidly and precisely reflects a laser beam to form projection imaging. The second technology is a Digital Light Processing (DLP) technology, in which an image is generated through a Digital Micromirror Device (DMD), and in the DMD, a matrix made up of micro lenses (precise and micro mirrors) is disposed on a semiconductor chip, and each micro lens controls one pixel in a projected frame. The third technology is a reflective Liquid Crystal on Silicon Color Sequence (LCoS CS) technology, in which a fixed light microscope on a surface of a chip is used, and the intensity of the light reflection is controlled through a liquid crystal array to project a finally constituted frame.
Compared with the DLP and the LCoS micro projection technology, the laser micro projection technology has the following advantages: the least power consumption (the power used by an embedded projection module is less than 1 W), the maximum size of the projected image (the size may exceed 100 inches), and no need to focus. In addition, the laser micro projection technology may provide 1080P extra high definition. In contrast, the definition of the current DLP and the LCoS micro projection products merely supports 480*320 pixels or VGA640*480 pixels.
One of the key technologies of the micro projector is that a rotation angle of the mirror should be large and a rotation frequency should be high. As for 800*600 pixels, to reach 30 frames per second, the velocity of a fast axis should be more than 18 kHz.
In order to achieve a high scanning velocity, in the prior art, a driving mode of the mirror in the current laser micro projection technology includes an electromagnetic mode and an electrostatic mode, so as to change the design of the mirror in response to various driving modes.